JP3182052B2 - Developer carrier - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developer carrier used in a developing device for developing a latent image formed on an image carrier such as an electrophotographic photosensitive member or an electrostatic recording derivative to visualize the latent image. It is about the body.

[0002]

2. Description of the Related Art Conventionally, a developing device for developing an electrostatic latent image formed on the surface of a photosensitive drum as an image carrier with toner of a one-component developer, for example, friction between toner particles, developer carrying Due to the friction between the toner particles and the developing sleeve as a body and the friction between the toner particles and the member that regulates the amount of toner applied on the developing sleeve, a positive or negative charge is given to the toner particles, and the toner is extremely deposited on the developing sleeve. A thin coating is applied and transported to a developing area where the photosensitive drum and the developing sleeve are opposed to each other. In the developing area, the toner flies to and adheres to the electrostatic latent image on the surface of the photosensitive drum and is developed, and the electrostatic latent image is visualized as a toner image. What is imaged is known.

[0003] As a developer carrier used for the development of the above-mentioned method, for example, a metal, an alloy thereof, or a compound thereof is formed into a cylindrical shape, and the surface thereof is brought to a predetermined surface roughness by electrolysis, blast, file, or the like. What was processed as mentioned above is used. However, in this case, the toner existing in the vicinity of the surface of the developer carrier in the toner layer formed on the surface of the developer carrier by the regulating member has a very high electric charge, and the toner is reflected on the surface of the carrier by the mirror force. It is strongly attracted. As a result, the chance of friction between the toner and the carrier is lost, and the toner cannot have a suitable charge.
Under such circumstances, sufficient development and transfer are not performed, resulting in an image having many image density unevenness and character scattering. In order to prevent the generation of toner having an excessive charge as described above and the strong adhesion of the toner, a film in which a conductive substance such as carbon black or graphite or a solid lubricant is dispersed in a binder resin is used as the developer. A method of forming a carrier on a carrier is proposed in Japanese Patent Application Laid-Open No. 3-36570. Further, the coating film is used for a durability test of a developing device (long-term use).
In order to stabilize the toner carrying property of the developer carrier, that is, to stabilize the surface roughness of the developer carrier,
A method in which spherical particles are further included in the coating is proposed in Japanese Patent Application Laid-Open No. 3-200986.

[0004]

However, in recent years, it has been desired to further improve the durability of the developer carrying member and to lower the temperature of the toner from the viewpoint of energy saving. The above method is not sufficient. For example, in the conventional LBP, it is sufficient that the developer carrier has a durable number of about 10,000 sheets and the image quality is stable, but recently, there is a model that requires a stable image quality of 30,000 sheets or more. Is required to further improve the abrasion resistance. Further, in order to fix the toner at a low temperature, instead of the conventional toner having a glass transition temperature Tg of 60 ° C. or more, T
Since some models use a toner having a g of 60 ° C. or less, the toner is easily affected by a rise in the temperature of the main body or the like and is easily fused to the developer carrying member. In such a model, in the latter half of the durability test, the surface roughness of the developer carrier is maintained, but graphite is missing from the coating, and the added spherical particles are exposed on the surface. The conductivity, lubricity and releasability of the carrier locally deteriorate on the surface of the carrier, and excessive charging of the toner and fusion of the toner to the surface of the carrier are likely to occur, which causes a reduction in image density. . Accordingly, an object of the present invention is to maintain the abrasion resistance of the coating film, stabilize the surface roughness and the charge imparting property to the toner even in the long-term durability test of the developing device more than the conventional one,
An object of the present invention is to provide a developer carrier in which fusion to a developer carrier is suppressed and image density hardly decreases. Another object of the present invention is to provide a developer carrier that can eliminate a sleeve ghost.

[0005]

According to the present invention, in a developer carrier for carrying a one-component developer for developing a latent image formed on an image carrier, a surface of the developer carrier is provided. And conductive spherical particles in 100 parts by weight of the binder resin.
3-200 developer carrying member spherical particles 3 to 200 parts by weight of oppositely charged the weight portion and the toner is characterized in that the coating layer is that is contains at least provided is provided.

The developer carrier of the present invention comprises a cylindrical substrate and a coating layer covering the surface of the substrate. The operation of the developer carrier of the present invention will be described with reference to FIG. 1, which is an example of the present invention. The coating layer 1 includes conductive treated spherical particles 2, spherical particles 3 having the opposite polarity to toner, and binder resin 5.
And, if necessary, the conductive substance 4 and / or the solid lubricant 6
And is coated on the cylindrical substrate 7. In such a developer carrying member, even if the coating layer 1 is worn out by the long-term durability test, the conductive particles 2 are exposed and the conductivity of the coating layer 1 is maintained, so that excessive charging of the toner is prevented. Also, the fusion of the toner onto the developer carrier is prevented. Further, since the toner is favorably charged by the spherical particles 3 which are charged in the opposite polarity to the toner, a good image density can be obtained even under high temperature and high humidity. Furthermore, since the spherical particles 2 subjected to the conductive treatment and the spherical particles 3 charged to the opposite polarity to the toner have spherical shapes, the surface roughness of the coating layer 1 is maintained even during the durability test, and the toner development The transportability to the section is also kept constant. For this purpose, the surface roughness of the coating should be J
The IS center line average roughness (Ra) is preferably in the range of 0.2 to 3.5 μm. When Ra is less than 0.2 μm, the amount of charge on the developer carrying member increases, and developability becomes insufficient. When Ra exceeds 3.5 μm, unevenness occurs in the toner coat layer on the developer carrying member, resulting in uneven density on an image.

Next, each material constituting the coating layer 1 will be described. Examples of the conductive spherical particles 2 include metal oxides such as zinc oxide, zinc sulfide, barium sulfate, titanium oxide, tin oxide, niobium oxide, manganese oxide, lead oxide, copper oxide, indium oxide, and iridium oxide. Coated composite metal oxide with a good conductive material,
Conductive treatment by doping with substances having different oxidation numbers; resin-based spherical particles such as phenolic resin; carbonized and / or graphitized by firing mesocarbon microbeads; The bulk mesophase pitch (mesophase, petroleum-based or coal-based pitch containing optically anisotropic liquid crystal is coarsely pulverized by a pulverizer such as a jaw crusher by a mechanochemical method, and then finely pulverized by a dry or wet ball mill. (Obtained by pulverization), heat-treated under a certain condition, and then fired, and carbonized on the surface to make the surface conductive. These are used alone or in combination of two or more. The volume average particle diameter of the conductive spherical particles 2 used in the present invention is preferably in the range of 0.2 to 50 μm. If it is less than 0.2 μm, it is difficult to obtain a suitable surface roughness of the developer carrying member, and the image quality is likely to deteriorate. If it exceeds 50 μm, it protrudes from the coating film, and undesired development tends to occur only in that portion, which is not preferable.

The spherical particles 3 charged to the opposite (opposite) polarity to the toner include (1) phenol resin, epoxy resin, melamine resin, silicone resin, methyl methacrylate resin (PMMA), Spherical particles of a positively-charged substance such as a methacrylate terpolymer such as polystyrene / n-butyl methacrylate / silane terpolymer, a styrene-butadiene-based copolymer, a nitrogen-containing polymer such as polycaprolactone, polyvinylpyridine, and polyamide. (2) For positively charged toner, polyvinylidene fluoride, polyvinyl chloride,
Polytetrafluoroethylene, polytetrachlorofluoroethylene, polyperfluoroalkoxylated ethylene, polytetrafluoroalkoxyethylene, fluorinated ethylene propylene-polytetrafluoroethylene copolymer, trifluorochloroethylene-vinyl chloride copolymer Spherical particles of a negatively charged substance such as a halogenated polymer, polycarbonate, and polyester can be used. These spherical particles are used alone or in combination of two or more. The particle diameter of the spherical particles 3 having the opposite polarity to that of the toner used in the present invention is preferably 0.1 to 50 μm. If the thickness is less than 0.1 μm, it is difficult to obtain a suitable roughness on the surface of the developer carrying member, and the image quality is likely to deteriorate. If it exceeds 50 μm, it protrudes from the coating film, and undesired development tends to occur only in that portion, which is not preferable.

Examples of the conductive substance other than the conductive spherical particles used for adjusting the resistance value of the film, if necessary, include metal powders such as aluminum, copper, nickel and silver, antimony oxide and indium oxide. And carbon oxides such as metal oxides such as tin oxide, carbon fiber, carbon black, and graphite. Among them, carbon black, especially conductive amorphous carbon, is particularly excellent in electric conductivity, and it is possible to obtain a wide range of conductivity by adding conductivity to polymer materials and controlling the amount of addition. It is preferably used. Particle size of conductive amorphous carbon is 10 to 80 mμm
Are preferred. These are also used alone or in combination of two or more.

Further, in order to further reduce the adhesion of the toner to the developer carrying member, a solid lubricant may be mixed in the coating as needed. Examples of the solid lubricant include molybdenum disulfide, boron nitride, graphite, graphite fluoride, silver-selenium niobium, calcium chloride-graphite, and talc. Among these, graphite is preferably used because it has conductivity together with lubricity, and has a function of reducing toner having an excessively high charge and providing a charge amount suitable for development.

The binder resin for forming the coating layer by dispersing the conductive spherical particles and the spherical particles charged to the opposite polarity to the toner includes phenolic resins, epoxy resins, polyamide resins, polyester resins, and polycarbonate resins. Resin, polyolefin resin, silicone resin,
Known resins such as a fluorine resin, a styrene resin, and an acrylic resin are used. In particular, a thermosetting or photocurable resin is preferable.

A coating for forming a coating film is prepared using each of the above-described components, and is applied to the surface of the developer carrying substrate so as to have a predetermined dry thickness and dried.
A developer carrier having a coating layer is obtained. The coating material usually contains conductive spherical particles or the like dispersed in a binder resin.
3 to 200 parts by weight of conductive spherical particles per 0 part by weight, 3 to 200 parts by weight of spherical particles charged to the opposite polarity to the toner, 0 to 200 parts by weight of a conductive substance other than the above, and / or 0 to 200 parts by weight of solid lubricant Parts, and uniformly mixed and dispersed in a binder solution. The method for producing the coating material is not particularly limited as long as it follows a conventional method. The coating material is applied to the surface of the developer substrate by a usual coating method such as spraying and dried, thereby forming a coating layer. The thickness of the coating layer is usually in the range of 2 to 200 μm.

Next, a developing device in which the developer carrier of the present invention is incorporated will be described with reference to FIGS. In FIG. 2, an image carrier for carrying an electrostatic latent image formed by a known process, for example, an electrophotographic photosensitive drum 8, is rotated in the direction of arrow B. The developing sleeve 15 serving as a developer carrier carries the magnetic toner 11 serving as a one-component magnetic developer supplied from the hopper 10 and rotates in the direction of arrow A, thereby causing the developing sleeve 1 to rotate.
The toner 11 is conveyed to the developing unit D where the photosensitive drum 5 and the photosensitive drum 8 face each other. In the developing sleeve 15, a magnet 12 is disposed for magnetically attracting and holding the magnetic toner 11 on the developing sleeve 15. The toner 11 is the developing sleeve 1
By the friction with the photosensitive drum 5, a triboelectric charge that enables the electrostatic latent image on the photosensitive drum 8 to be developed is obtained.

In order to regulate the layer thickness of the magnetic toner 11 conveyed to the developing section D, a regulating blade 9 made of a ferromagnetic metal is moved from the surface of the developing sleeve 15 by about 200 to 300 μm.
It is hung from the hopper 10 so as to face the developing sleeve 15 with a gap width of m. By the magnetic field lines from the magnetic pole N1 of the magnet 12 being concentrated on the blade 9,
A thin layer of the magnetic toner 11 is formed on the developing sleeve 15. As the blade 9, a non-magnetic blade can be used.

The thickness of the thin layer of the magnetic toner 11 formed on the developing sleeve 15 is preferably smaller than the minimum gap between the developing sleeve 15 and the photosensitive drum 8 in the developing section D. The present invention is particularly effective for a developing device of a type that develops an electrostatic latent image with such a thin toner layer, that is, a non-contact type developing device. However, in the developing section, the thickness of the toner layer is
The present invention can also be applied to a developing device having a thickness not less than the minimum gap between them, that is, a contact type developing device. In order to avoid the complexity of the description, a non-contact developing device will be described below as an example.

A power supply 16 applies a developing bias voltage to the developing sleeve 15 so that the magnetic toner 11 which is a one-component magnetic developer carried on the developing sleeve 15 flies. When a DC voltage is used as the developing bias voltage, a voltage having a value between the potential of the image portion of the electrostatic latent image (the area where the toner 11 adheres and is visualized) and the potential of the background portion is used. Is preferably applied. on the other hand,
An alternating bias voltage is applied to the developing sleeve 15 to increase the density of the developed image or improve the gradation.
An oscillating electric field whose direction is alternately reversed may be formed in the developing unit D. In this case, it is preferable to apply to the developing sleeve 15 an alternating bias voltage on which a DC voltage component having a value between the potential of the image portion and the potential of the background portion is superimposed.

In so-called regular development in which toner is adhered to a high potential portion of an electrostatic latent image having a high potential portion and a low potential portion to visualize the toner, a toner charged to a polarity opposite to the polarity of the electrostatic latent image is used. On the other hand, in so-called reversal development in which toner is adhered to a low-potential portion of an electrostatic latent image to visualize the toner, a toner charged to the same polarity as the polarity of the electrostatic latent image is used. In addition, high potential,
Low potential is an expression based on an absolute value. In any case, the toner 11 is charged to a polarity for developing the electrostatic latent image by friction with the developing sleeve 15. Toner 11
Is also charged by friction with the developing sleeve 15.

FIG. 3 is a block diagram showing another example of the developing device of the present invention, and FIG. 4 is a block diagram showing still another example of the present invention. In the developing device of FIGS. 3 and 4, as a member that regulates the layer thickness of the magnetic toner 11 on the developing sleeve 15,
An elastic plate 18 made of a material having rubber elasticity such as urethane rubber or silicone rubber or a metal elastic material such as phosphor bronze or stainless steel is used.
In the developing device of FIG. 4, the developing sleeve 15 is pressed against the developing sleeve 15 in a direction opposite to the rotational direction.
It is characterized in that it is brought into pressure contact with the body in the same direction as the rotation direction. In such a developing device, a thinner toner layer can be formed on the developing sleeve 15.

Other configurations of the developing device shown in FIGS. 3 and 4 are basically the same as those of the developing device shown in FIG.
2, the same reference numerals as those shown in FIG. 2 indicate the same members. 3 and 4 for forming a toner layer on the developing sleeve 15 as described above, a developing device using a one-component magnetic developer containing a magnetic toner as a main component may be used as a non-magnetic toner. It is also suitable for those using a one-component non-magnetic developer whose main component is. In any case, since the toner is rubbed on the developing sleeve 15 by the elastic plate 18, the amount of triboelectric charge of the toner is increased, and the image density is improved.

[0020]

The present invention will be described below in detail with reference to examples. Unless otherwise specified, parts and percentages in the following Examples and Comparative Examples are based on weight. The average particle size is a volume average particle size.

[0021] Example 1 Phenol 20 parts resin 200 parts Graphite isopropyl alcohol (IPA) 220 parts The above materials performed 10 hours a sand mill at zirconia particles having a diameter of 2 mm, and separated in the subsequent sieving zirconia particles, solids 50% solid lubricant-containing binder resin (binder) dispersion (stock solution 1) (graphite / binder =
0.2 / 2). The above material was subjected to a sand mill for 1 hour using glass beads having a diameter of 3 mm, and then the glass beads were separated by sieving.
Paint 1 (0.2-conductive treated TiO ₂ spherical particles / 50-PMMA spherical particles: L (solid lubricant) / C (conductive substance) / RC (conductive spherical particles) ) / B (binder resin) / RT (spherical particles charged to the opposite polarity to the toner) = 0.2 / 0 / 0.7 / 2/0.
1) was obtained (the value before the spherical particles represents the average particle size μm; the same applies to the following examples).

This paint is applied by spraying onto an Al cylinder having a diameter of 16 mm so as to form a film having a dry thickness of 10 μm, and then heated and cured by a hot air drier at 150 ° C. for 30 minutes to carry out the developer carrier. Was prepared. When the surface roughness of this film was measured, it was Ra = 2.0 μm. Further, the same paint as paint 1 was obtained except that PMMA spherical particles of paint 1 having an average particle diameter of 60 μm were used, and a developer carrier (Ra = 2.0 μm) was prepared using this paint.
These developer carriers (sleeve) are incorporated into a laser jet Si (HP LBP), 10 ° C., 10%
Image formation was performed in two environments of low temperature and low humidity (L / L) of RH and high temperature and high humidity (H / H) of 30 ° C. and 80% RH.

As a developer, 1.2 μm of colloidal silica was added to a toner having a weight average particle diameter of 6 μm adjusted according to the following formulation.
% Externally added was used. In addition, the particle size of the conductive spherical particles is Coulter LS-130.
It measured with the laser diffraction type particle size distribution meter (made by Coulter). On the other hand, the average particle diameter of the spherical particles charged to the opposite polarity to the toner was measured with a Coulter Multisizer (manufactured by Coulter Inc.) using a 100 μm aperture. The same Oite the following examples.

Image characteristics and various characteristics of the sleeve were evaluated by the following methods and criteria. This is the same in the following examples. [Image Characteristics] Image densities after image formation of 10, 20,000 and 40,000 sheets were visually evaluated for ghosts using a Macbeth reflection densitometer, and the evaluation results were indicated by the following indices. (1) Image density (Macbeth reflection density) ： １: 1.4 or more ：: 1.2 or more and less than 1.4 Δ: 1.0 or more and less than 1.2 ×: less than 1.0 (2) Ghost (visual) ◎ : excellent ○: good △: practically accepted ×: surface roughness after impractical [film strength] (1) roughness change (represented by delta Ra) initial developer carrying member was coated coat and 40,000 image output Ra surf coder SE-3 manufactured by Kosaka Laboratory
At 300, 3 points in the axial direction × 2 points in the circumferential direction = 6 points were measured, and the average value was obtained. (2) Abrasion (expressed by Δ film thickness) The outer diameter of the coated developer carrier at the initial stage and after image output of 40,000 sheets is measured with a laser three-dimensional measuring device, and the shaved amount is determined from the decrease in outer diameter. Calculated. Table 1 shows the above results. still,
The upper row in the table shows the results when the average particle diameter of the PMMA spherical particles is 50 μm, and the lower row shows the results when the average diameter is 60 μm. Both were good results.

Embodiment 2 The above material was subjected to a sand mill for 1 hour using glass beads having a diameter of 3 mm, and then the glass beads were separated by sieving.
Paint 2 (0.2-conductive treated TiO ₂ spherical particles / 50-nylon spherical particles: L / C
/RC/B/RT=0/0/0.9/2/0.1) and a developer carrier (Ra = 1.9) in the same manner as in Example 1.
μm). Further, the same paint as paint 1 was obtained except that the conductive-treated TiO ₂ spherical particles were replaced with the particles having an average particle diameter of 0.1 μm, and a developer carrier (Ra = 1.
8 μm). These developer carriers were used in Example 1.
The evaluation was performed in the same manner as described above, and the results shown in Table 1 were obtained. In the upper part of the table, the average particle diameter of the conductive treated TiO ₂ spherical particles is 0.2 μm.
In the case of (1), the lower stage shows the result in the case of 0.1 μm. Both were good results.

Embodiment 3 Using the same material as in Example 1, paint 3 (0.2-T
i-Ni-Sb oxide spherical particles / 15-PMMA spherical particles: L / C / RC / B / RT = 0.2 / 0 / 0.5 / 2
/0.3), and using this, a developer carrying member (Ra = 1.8 μm) was produced in the same manner as in Example 1. This developer carrier was evaluated in the same manner as in Example 1. Table 1 shows the evaluation results.
Shown in Good results were obtained after 10 images, after 20,000 images and after 40,000 images.

Embodiment 4 With the above materials, paint 4 (0.4
-Ti-Ni-Sb oxide spherical particles / 15-nylon spherical particles: L / C / RC / B / RT = 0/0 / 0.7 / 2
/0.3), a developer carrier (Ra = 1.7 μm) was prepared in the same manner as in Example 1, and evaluated in the same manner as in Example 1. Table 1 shows the evaluation results. After 10 images, 2
Good results were obtained both after 10,000 sheets and after 40,000 sheets.

[0028] carried out 10 hours a sand mill Example 5 Phenol resin 200 parts Graphite 30 parts IPA 230 parts The above materials in zirconia particles having a diameter of 2 mm, then separated by sieving the zirconia particles, solid content of 50% solids Dispersion of lubricant-containing binder resin (stock solution 2) (graphite / binder = 0.3 / 2)
I got Using this, paint 5 (5-spherical carbon particles, 0.1-PMMA spherical particles: L / C / RC / B / RT = 0.3 / 0 / 0.4) in the same manner as in Example 1 with the following formulation. / 2
/0.3). - stock solution 2 230 parts Spherical carbon particles (average particle size 5 [mu] m) 20 parts PMMA spherical particles (average particle size 0.1 [mu] m) using 15 parts of paint 5, in the same manner as in Example 1 developer carrying member (Ra = 1.7 μm), and imaged and evaluated in the same manner as in Example 1. Table 1 shows the evaluation results. Good results were obtained after 10 images, after 20,000 images and after 40,000 images.

[0029] Example 6 Phenol resin 100 parts Spherical carbon particles (average particle size 5 [mu] m) 25 parts Nylon spherical particles (average particle size 0.1 [mu] m) as in Example 1 using 25 parts IPA 0.99 parts The above materials 6 (5-spherical carbon particles / 0.1 nylon spherical particles: L / C / RC /
B / RT = 0/0 / 0.5 / 2 / 0.5), and a developer carrier (Ra = 1.9 μm) was prepared in the same manner as in Example 1.
An image was formed and evaluated in the same manner as in Example 1. Table 1 shows the evaluation results.
Shown in Good results were obtained after 10 images, after 20,000 images and after 40,000 images.

[0030] EXAMPLE 7 Phenol resin 200 parts Graphite 30 parts Carbon black 20 parts IPA 250 parts 50% solids by the same process as in Example 1 using the above material
Of a binder resin containing a solid lubricant (stock solution 3) (graphite / carbon black / binder = 0.3 / 0.
2/2) was obtained. Using this, paint 7 (50-spherical carbon particles, 0.1-P
MMA spherical particles: L / C / RC / B / RT = 0.3 /
0.2 / 0.1 / 2 / 0.4). · Stock 3 250 parts Spherical carbon particles (average particle size 50 [mu] m) 5 parts PMMA spherical particles (average particle size 0.1 [mu] m) with 20 parts of paint 7, in the same manner as in Example 1 developer carrying member (Ra =
1.7 μm). Further, a coating material was prepared in which the PMMA spherical particles of the coating material 7 were replaced with particles having an average particle size of 0.05 μm, and this was used to prepare a developer carrier (Ra = 1.6 μm).
m) was prepared. These developer carriers were imaged in the same manner as in Example 1 and evaluated. Table 1 shows the evaluation results. still,
In the upper row of the table, the average particle size of the PMMA spherical particles is 0.1 μm.
In the case of (1), the lower part shows the result of the case of 0.05 μm. Both were good results.

[0031] EXAMPLE 8 Phenol resin 200 parts Carbon black 50 parts IPA 250 parts The above materials performed 10 hours a sand mill at zirconia particles having a diameter of 2 mm, then separated by sieving the zirconia particles, solid content of 50% Dispersion of conductive binder resin (stock solution 4)
(Carbon black / binder = 0.5 / 2) was obtained. Using this, paint 8 (50-spherical carbon particles / 0.1-nylon spherical particles: L / C / RC / B / RT = 0 / 0.5 / 0) in the same recipe as in Example 1 with the following formulation. .1 / 2
/0.4). - stock 4 250 parts Spherical carbon particles (average particle size 50 [mu] m) 5 parts nylon spherical particles (average particle size 0.1 [mu] m) with 20 parts of paint 8, similarly to Example 1 developer carrying member (Ra =
1.9 μm). In addition, a coating material was obtained in which the spherical carbon particles of the coating material 8 were replaced with particles having an average particle size of 60 μm, and this was applied to prepare a developer carrying member (Ra = 2.0 μm). These developer carrying member was evaluated out image in the same manner as the actual Example 1. Table 1 shows the evaluation results. In addition, the upper part of the table is the case where the average particle size of the spherical carbon particles is 50 μm, and the lower part is 6
It is a result in the case of 0 μm. Both were good results.

[0032] Comparative Example 1 Phenol resin 200 parts Graphite 80 parts Carbon black 20 parts IPA 300 parts The above materials performed 10 hours a sand mill at zirconia particles having a diameter of 2 mm, and separated in the subsequent sieving zirconia particles, solid 50% dispersion of conductive binder resin (stock solution 5)
(Graphite / carbon black / binder = 0.
8 / 0.2 / 2). This is solidified with IPA to 30
%, And the developer carrier (Ra) was adjusted in the same manner as in Example 1.
= 1.0 μm). This developer carrier was evaluated in the same manner as in Example 1. Table 1 shows the results. The image density was low from the beginning, and the decrease in Ra was remarkable. After 20,000 sheets, toner fusion occurred.

[0033] Comparative Example (Comparative Example 1) 2 stock solution 5 300 parts phenol spherical particles with an (average particle size 20 [mu] m) 5 parts The above materials in the same manner as in Example 1 paint N (20- phenol spherical particles: L / C / RC / B / R (spherical particles) =
0.8 / 0.2 / 0/2 / 0.1), and a developer carrier (Ra = 1.9 μm) was obtained using this paint in the same manner as in Example 1.
m) was prepared. This was evaluated in the same manner as in Example 1. Table 1 shows the results. There were no problems after 10 and 20,000 sheets of image formation, but after 40,000 sheets, ghost deterioration due to excessive charging of the toner, image density reduction due to toner fusion, surface roughness reduction, and film shaving were large.

[0034]

Example 9 In Example 1, the PMMA spherical particles were replaced with an average particle diameter of 50 μm.
Example 1 except for replacing the polyester spherical particles of
Paint 9 (0.2-conductive treated Ti)
O ₂ spherical particles / 50-polyester spherical particles: L / C /
RC / B / RT = 0.2 / 0 / 0.7 / 2 / 0.1), and the developer was carried in the same manner as in Example 1 except that this coating material was applied to an aluminum sleeve having a diameter of 20 mm. Body (Ra
= 2.0 μm). A developer carrier (Ra = 2.0 μm) was prepared in the same manner as above, except that the above-mentioned polyester spherical particles were replaced with the particles having an average particle size of 60 μm. These developer carriers (sleeve) are NP6
030 (a copier made by Canon Inc.) incorporated in an elastic body modified into an elastic body, low temperature and low humidity (L / L) at 10 ° C. and 10% RH, and high temperature and high humidity (H / H) at 30 ° C. and 80% RH. H) Image output was performed in two environments.

As the developer, a toner prepared by the following formulation and having a weight average particle diameter of 6 μm and externally added 1.2% of colloidal silica treated with amino-modified silicone oil was used. Using the same evaluation method as in Example 1, evaluation was performed after 10 images, after 30,000 images and after 50,000 images, and the results shown in Table 2 were obtained. In the upper row of the table, the particle size of the polyester spherical particles is 5
In the case of 0 μm, the lower part shows the result in the case of 60 μm.
Both were good results.

Example 10 In Example 2, the nylon spherical particles were changed to an average particle diameter of 50 μm.
Paint 10 (0.2-conductive treated TiO _{2) by} the same formulation and manufacturing method as in Example 1 except that the Teflon spherical particles
Spherical particles / 50-Teflon spherical particles: L / C / RC / B
/RT=0/0/0.9/2/0.1), and was applied in the same manner as in Example 1 except that this was applied to an aluminum sleeve having a diameter of 20 mm (Ra = 1. 9 μm). Further, a developer carrier (Ra = 1.8 μm) was prepared in the same manner as described above, except that the electrically-conductive TiO ₂ spherical particles of the coating material 10 were replaced with the particles having an average particle diameter of 0.1 μm. These developer carriers were evaluated for image formation in the same manner as in Example 9, and the results shown in Table 2 were obtained. The upper row in the table shows the results when the particle diameter of the conductive treated TiO ₂ spherical particles is 0.2 μm, and the lower row shows the results when the particle diameter is 0.1 μm. Both were good results.

Example 11 In Example 3, the PMMA spherical particles were changed to an average particle size of 15 μm.
Paint 11 (0.4-conductive treated Ti) with the same formulation and manufacturing method as in Example 3 except that the polyester spherical particles
-Ni-Sb oxide spherical particles / 15-polyester spherical particles: L / C / RC / B / RT = 0.2 / 0 / 0.5 /
2 / 0.3) was obtained, and a developer carrier (Ra = 1.8 μm) was produced in the same manner as in Example 1 except that this was applied to an aluminum sleeve having a diameter of 20 mm. Example 9
The image was formed and evaluated in the same manner as described above. Table 2 shows the results. Good results were obtained after 10, 30, 30, and 50,000 images.

Example 12 In Example 4, the nylon spherical particles were changed to an average particle diameter of 15 μm.
Paint 12 (0.4-conductive-treated Ti-N) by the same formulation and manufacturing method as in Example 4 except that Teflon spherical particles of
i-Sb oxide spherical particles / 15-Teflon spherical particles: L
/C/RC/B/RT=0/0/0.7/2/0.3)
And a developer carrying member (Ra = R) was obtained in the same manner as in Example 1 except that this was coated on an aluminum sleeve having a diameter of 20 mm.
1.7 μm). This was imaged in the same manner as in Example 9 and evaluated. Table 2 shows the results. After 10 images, 3
Good results were obtained both after 10,000 and 50,000 sheets.

Example 13 In Example 5, the PMMA spherical particles were prepared with an average particle size of 0.1 μm.
Example 5 except for replacing the polyester spherical particles of
Paint 13 (5-spherical carbon particles.
0.1-polyester spherical particles: L / C / RC / B / R
T = 0.3 / 0 / 0.4 / 2 / 0.3), and a developer carrier (Ra = 1) was obtained in the same manner as in Example 1 except that this was applied to an aluminum sleeve having a diameter of 20 mm. .7 μm). This was evaluated in the same manner as in Example 9. Table 2 shows the results. Good results were obtained after 10, 30, and 50,000 sheets.

Example 14 In Example 6, the nylon spherical particles were prepared by changing the average particle diameter to 0.1 μm.
Paint 14 (5-spherical carbon particles, 0.1-μm) was prepared in the same manner as in Example 6 except that m-teflon spherical particles were used.
Nylon spherical particles: L / C / RC / B / RT = 0/0 /
0.5 / 2 / 0.5), and the developer carrier (Ra)
= 1.9 μm). This was imaged in the same manner as in Example 9, and the evaluation results are shown in Table 2. Good results were obtained after 10, 30, and 50,000 sheets.

Example 15 In Example 7, the PMMA spherical particles were prepared with an average particle size of 0.1 μm.
Example 7 except for replacing the polyester spherical particles of
Paint 15 (50-spherical carbon particles / 0.1 polyester spherical particles: L / C / RC / B / R)
T = 0.3 / 0.2 / 0.1 / 2 / 0.4), and was applied to a developer carrier (Ra) in the same manner as in Example 1 except that this was applied to an aluminum sleeve having a diameter of 20 mm. = 1.7μ
m) was prepared. Further, a developer carrying member (Ra = 1.6 μm) was prepared in the same manner as above, except that the above-mentioned polyester spherical particles were changed to an average particle diameter of 0.05 μm. These developer carriers were imaged in the same manner as in Example 9 and evaluated. Table 2 shows the results. The upper row in the table shows the results when the particle diameter of the polyester spherical particles is 0.1 μm, and the lower row shows the results when the particle diameter is 0.05 μm. Both were good results.

Example 16 The same procedure as in Example 8 was repeated except that the spherical nylon particles had an average particle size of 0.1 μm.
m of Teflon spherical particles of paint 16 (50-spherical carbon particles.
0.1-Teflon spherical particles: L / C / RC / B / RT =
0 / 0.5 / 0.1 / 2 / 0.4), which has a diameter of 2
Example 1 except that it was coated on a 0 mm aluminum sleeve
A developer carrying member (Ra = 1.9 μm) was produced in the same manner as in the above. Further, the spherical carbon particles of the paint 16 have an average particle diameter of 60.
The developer carrier (Ra
= 2.0 μm). Using these sleeves,
An image was formed and evaluated in the same manner as in Example 9. Table 2 shows the results. The upper row in the table shows the results when the particle diameter of the spherical carbon particles is 50 μm, and the lower row shows the results when the particle diameter is 60 μm. Both were good results.

Comparative Example 3 A dispersion of a conductive binder resin (stock solution 6) was prepared in the same manner as in Comparative Example 1 except that the phenol resin was replaced with a polycarbonate resin and the phenol spherical particles were replaced with polycarbonate spherical particles. I got This was adjusted to a solid content of 30% with IPA, and a developer carrier (Ra = 1.0 μm) was produced in the same manner as in Example 9. Table 2 shows the evaluation results. The image density was low from the beginning, and the decrease in Ra was remarkable. After 30,000 sheets, toner fusion occurred.

Comparative Example 4 Paint P [20-polycarbonate spherical particles: L / C / R /
C / B / R (spherical particles = 0.8 / 0.2 / 0/2/0.
1)] was obtained, and the developer carrier (Ra) was obtained in the same manner as in Example 9.
= 1.9 μm). Table 2 shows the evaluation results. 1
No problem occurred after 0 and 30,000 sheets, but after 50,000 sheets, ghost deterioration due to excessive charging of the toner, image density reduction due to toner fusion, surface roughness reduction, and film shaving were large.

[0046]

[0047]

As described above, according to the present invention, the abrasion resistance of the surface film of the developer carrier is remarkably improved even in a long-term durability test of a developing device for electrophotography or electrostatic recording, which is longer than the conventional one. In addition, effects such as stabilization of surface roughness and charge imparting property to the toner and suppression of excessive charging of the toner and fusion of the toner onto the developer carrying member are exhibited. As a result, it is possible to stably obtain a high-quality image for a long period of time without causing a decrease in image density or a sleeve ghost even at a low temperature and a low humidity and at a high temperature and a high humidity.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a cross section of a part of a developer carrier of the present invention.

FIG. 2 shows an example of a developing device in which the developer carrier of the present invention is incorporated.

FIG. 3 shows another example of a developing device in which the developer carrier of the present invention is incorporated.

FIG. 4 shows another example of a developing device into which the developer carrier of the present invention is incorporated.

[Explanation of symbols]

 1: Spherical particles treated electrically conductive 3: Spherical particles charged to the opposite polarity to toner 4: Conductive substance 5: Binder resin 6: Solid lubricant 7: Cylindrical substrate 8: Photosensitive drum 9: Regulator blade 10: Hopper 11: Toner 12: Magnet 13: Cylindrical substrate 14: Coating layer 15: Developing sleeve 16: Power supply 17: Stirrer 18: Elastic plate A: Rotating direction of developing sleeve B: Rotating direction of photosensitive drum D : Development unit

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yasuhide Goseki 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (56) References JP-A-6-202455 (JP, A) JP-A Heisei 3-200986 (JP, A) JP-A-4-166864 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03G 13/08-13/095 G03G 15/08-15 / 095

Claims (5)

(57) [Claims] 1. A developer carrier for carrying a one-component developer for developing a latent image formed on an image carrier, wherein a conductive resin is contained on a surface of the developer carrier in 100 parts by weight of a binder resin. developer carrying member spherical particles 3 to 200 parts by weight of oppositely charged spherical particles 3 to 200 parts by weight of the toner, characterized in that the coating layer that is contained at least is provided. 2. The developer carrier according to claim 1, wherein the binder resin further contains a conductive substance other than the conductive spherical particles and / or a solid lubricant. 3. The conductive spherical particles have a volume average particle size of 0.2.
Developer carrying member according to claim 1 or 2 is ～50Myuemu. 4. The method of claim 1 to 3 volume average particle diameter of the spherical particles charged toner and opposite polarity is 0.1~50μm
The developer carrier according to any one of the above . 5. The conductive spherical particles may be a metal oxide or a composite.
Of a conductive material against spherical metal oxide particles
And / or doping of substances with different oxidation numbers,
Conductive conductive spherical particles or spherical carbon particles
A developer carrier according to any one of claims 1 to 4.